It is common in the art to control the delivery of items from a bulk supply by providing a switch which is operated by an excess of such items at a given place in the processing of the items to stop delivery and when the excess has dissipated to restore delivery. In the Sterling U.S. Pat. Nos. 3,164,291 and 3,164,292 and the Everett U.S. Pat. No. 2,985,338 a counterweighted plate is employed over which items are moved which is operable if an excess of items depresses it to stop delivery of the items until the excess items have been removed. It is also known in the art of processing items to effect their movement from one place to another during processing by air jets placed to drive the items along a narrow passage. This invention is designed to take advantage of the use of such a driving jet and the accumulation of an excess number of items to control the delivery of items from the bulk supply.